#define _CRT_SECURE_NO_WARNINGS 1
#include<iostream>
#include<vector>
using namespace std;
class Solution {
public:
    int singleNumber(vector<int>& nums)
    {
        int singleNumber = 0;
        for (auto num : nums)
        {
            singleNumber ^= num;
        }
        return singleNumber;
    }
};
